LAWS OF MOTION

Answer :

F = ma

                   same force is acting on both masses.

                             F = m₁ a₁ = m₂ a₂ = constant

                             (a₂ / a₁) = (m₁ / m₂)

                   also v = v_o + at

                   here v_o = 0

                             v = at

                             v = a₁ t₁ = a₂ t₂ = constant

                             (t₁ / t₂) = (a₂ / a₁)

                   Hence (t₁ / t₂) = (a₂ / a₁) = (m₁ / m₂) = (1 / 2) = 1 : 2   

Answer :

Force is the quantity when measured from different frames is same. 

Answer :

No of balls = 10000

                   mass of each ball = 1g.

                   area = 1 cm² = 10^–4 m²

                   pressure = {(Force) / (area)} = (ma / A) = [{no of balls × mass of each ball

                                                                × change in velocity per unit time} / {Area}]

                   Pressure = [{10000 × 10^–3 × (v – (– v))} / {10^–4}] = as ball rebound with

                   same velocity hence v₂ = – v

                             = [{10000 × 10^–3 × 2 × 100} / {10^–4}]

                             = 2 × 10⁷ N/m²    

Answer :

momentum = mass × velocity

velocity is doubled hence momentum all get doubled.

Answer :

P = P_x i˄ + P_yj˄

                   P = 2 cos t i˄ + 2 sin t j˄

                   F = (d / dt) (p) = (d / dt) (2 cos t i˄ + 2 sin t j˄)

                   F = – 2 sin t i˄ + 2 cos t j˄

                   cos θ = {(F ∙ P) / (|F||P|)}

                   F ∙ P = (– 2 sin t i˄ + 2 cos t j˄)(2 cos t i˄ + 2 sin t j˄)

                             = – 4 sin t cos t + 4 sin t cos t

                             = 0

                   cos θ = 0

                   θ = 90°